Thanks Peter and Davy.
As it turned out problem was due to contactor points gap.
Went through the suggestions, checked plugs, distributor to coil earth strap, fuel filters, tracking on distributor cap and condensor.
When it came to the points it turned out the gap was less than 0.2mm, could have been as low as 0.1.
Set the gap back to 0.4mm and away it went. Also improved the tickover, had to adjust it back and the car seems more lively out on the road.
David
Non Member